title: Reliability analysis of shoulder balance measures: comparison of the 4 available methods.
abstract: METHODS
  Observational study with 3 examiners.
  
  
  OBJECTIVE
  To compare the reliability of shoulder balance measurement methods.
  
  
  BACKGROUND
  There are several measurement methods for shoulder balance. No reliability analysis has been performed despite the clinical importance of this measurement.
  
  
  METHODS
  Whole spine posteroanterior radiographs (n = 270) were collected to compare the reliability of the 4 shoulder balance measures in patients with adolescent idiopathic scoliosis. Each radiograph was measured twice by each of the 3 examiners using 4 measurement methods. The data were analyzed statistically to determine the inter- and intraobserver reliability.
  
  
  RESULTS
  Overall, the 4 radiographical methods showed an excellent intraclass correlation coefficient regardless of severity in intraobserver comparisons (>0.904). In addition, the mean absolute difference values in all methods were low and were comparatively similar (<1.73°). However, in interobserver comparisons, reliabilities were significantly decreased in the less severe radiographs, firstly on radiographical shoulder height measures (intraclass correlation coefficients >0.445, mean absolute difference <3.91°). However, the intraclass correlation coefficients in the coracoid height difference and clavicular angle methods were in the excellent range (>0.810 and >0.787, respectively) regardless of severity. In addition, the mean absolute difference values in the clavicular angle method were lower (<0.62°) than others.
  
  
  CONCLUSIONS
  The higher reliability of the clavicular angle and coracoid height difference methods indicate the clinical usefulness of these methods. Physicians should selectively use the shoulder balance measurement method clinically.
  
  
  METHODS
  3.
authors.affiliation: *Department of Orthopedics, Korea University Ansan Hospital, Ansan, South Korea †Department of Orthopedics, Korea University Guro Hospital, Seoul, South Korea; and ‡Department of Orthopedics, Korea University Anam Hospital, Seoul, South Korea.
authors.forename: Jae-Young
authors.initials: JY
authors.lastname: Hong
authors.forename: Seung-Woo
authors.initials: SW
authors.lastname: Suh
authors.forename: Jae-Hyuk
authors.initials: JH
authors.lastname: Yang
authors.forename: Si-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Han
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011859:Radiography / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012782:Shoulder / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013131:Spine / Q000000981:diagnostic imaging* / Q000503:physiopathology